Circutor GETEST MPC-5, Инструкция по эксплуатации

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17
Instructions Manual
GETEST
4�4�- TEST TYPES
4�4�1�- CONNECTION OF THE HARDWARE GROUND AND AUXILIARY GROUND
Connect one of the current
injection terminals
of the
GETEST
(
Ip
) to the hardware or protection
ground of the transformation centre or substation.
Do not confuse the hardware ground fittings with the service ground, even though in some
grounding systems these are interconnected.
Connect the other current injection terminal of the GETEST ( Ip ) to the auxiliary ground, which must
be performed beforehand. By means of an example, if you wish to inject 5 A, you must have a sum of
ground that does not exceed 110 Ω and to inject 50 A, this must not exceed 10 Ω.
Figure 8: Hardware ground connection details�
A good auxiliary ground must be sought out or built, since it will be the one that will
determine if the device can inject the test current.
Taking into account that the ohmic value of the hardware earth cannot be reduced,
an auxiliary ground with a reduced resistance must be sought.
In the case of using spikes to form the auxiliary ground, its ohmic value can be reduced
by adding more spikes in lockstep, moistening the ground, driving the spikes deeper, etc.
There are several options to create an auxiliary ground:

Use the neutral ground of the installation, as long as it is not connected to the hardware ground
fitting.

Drive several spikes in parallel, at a certain distance from each other.

Use ground from other elements outside the transformation centre or substation.
Supports Spikes system Neutral ground
Figure 9: Auxiliary grounds�